For the ELT, a total of 931 M1 Segment Assemblies will be manufactured. These will be of 133 different types, 7 copies each, with different optical and mechanical properties. The manufacturing of the segment support, the glass blank and the polishing will be done by industrial partners. ESO will be responsible for the shipment of the Segment Assemblies to Chile, for the integration of the edge sensors and their electronics, and for the cleaning and coating. After performing several health- and quality-checks, the Segment Assemblies will be temporarily stored in the warehouse, before being installed at the telescope and eventually recoated around every 2 years. The telescopes and instruments for optical astronomy are usually prototypes, while a new approach is required to manage such a series production of crucial components, which differ in small but significant aspects. In this paper, we will present the processes we have developed to manage the series production of M1 Segment Assemblies for the ELT, starting from the reception of the Segment Assemblies in Chile, inspection, installation of sub-components, health-checks, storage, and installation at the telescope.
EELT AIV is the activity of assembly, integration and verification of EELT (European Extremely Large Telescope) subsystems to deliver a telescope capable of fulfilling its top-level requirements and ready to start science commissioning, leading to operations. The AIV (Assembly Integration Verification) phase covers all technical activities on Armazones and nearby Paranal Observatory from the moment the sub-systems and components are delivered or accepted on-site (from the responsible sub-system project manager). AIV includes final system tests of the completed telescope (known as “Technical Commissioning”) and the installation, alignment and telescope integration of the science instruments. The AIV phase ends with the handover of the completed telescope with installed instruments, to the start of Science Commissioning. Responsibility then passes to the Commissioning team, however the technical resources for debugging and tuning the telescope and instrument will come from a combination of the AIV team working together with the Paranal operations staff. AIV is one of the major technical challenge of E-ELT. The sheer scale and complexity of the telescope involves challenging logistics and scheduling i.e. 798 mirror segments with a staged delivery over four years, including 9,048 edge sensor and 2,394 position actuators. More than ten major sub-systems e.g. M2-3-4-5, PreFocal Station (PFS) and instruments will be integrated and tested in parallel. Finally, the technical commissioning phase will be a significant challenge. E-ELT is a highly complex active telescope system with a fully-integrated adaptive optics (AO) system. During early testing nothing will be straightforward and there will be many system-level problems to overcome. It will take a dedicated team of the “best of the best” people to troubleshoot, debug, tune, and hand over as an operational facility.
The E-ELT is an active and adaptive 39-m telescope, with an anastigmat optical solution (5 mirrors including two flats), currently being developed by the European Southern Observatory (ESO). The convex 4-metre-class secondary mirror (M2) is a thin Zerodur meniscus passively supported by an 18 point axial whiffletree. A warping harness system allows to correct low order deformations of the M2 Mirror. Laterally the mirror is supported on 12 points along the periphery by pneumatic jacks. Due to its high optical sensitivity and the telescope gravity deflections, the M2 unit needs to allow repositioning the mirror during observation. Considering its exposed position 30m above the primary, the M2 unit has to provide good wind rejection. The M2 concept is described and major performance characteristics are presented.
Conference Committee Involvement (5)
Ground-based and Airborne Telescopes X
16 June 2024 | Yokohama, Japan
Ground-based and Airborne Telescopes IX
17 July 2022 | Montréal, Québec, Canada
Ground-based and Airborne Telescopes VIII
14 December 2020 | Online Only, California, United States
Ground-based and Airborne Telescopes VIII
13 December 2020 | San Diego, California, United States
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